Location: Cement Creek Area
Date of Observation: 12/08/2019
Name: Cosmo

Subject: Cement Creek storm total
Aspect:
Elevation: 9400

Avalanches:
Weather: 9” new snow from Sunday storm, Cement Creek @ 9400’
Snowpack:

Photos:

Location: Kebler Pass Area
Date of Observation: 12/08/2019
Name: Joey Carpenter

Subject: AMR Buried Surface Hoar
Aspect: North, North East
Elevation: 10200-11400

Avalanches:

None observed.

Weather: 9a-230p at the Anthracites. Snowfall rates varied from NO snow to S5 rates for brief periods. Overnight plus daytime accumulation totaled at ~13cm. It was still snowing hard when we left. Snow type and quality shifted from stellars, to graupel, to fat “wet” flakes, back to graupel, back to fatties through the day. OVC skies broke at times for periods of 6/8 cloud coverage making for beautiful light. Mostly no wind with brief periods of light but shifty in direction, predominantly NW. These periods of wind came with light snow transport at the NTL elevations we traveled in.
Snowpack: We experienced a very talkative snowpack today with too many small to medium collapses to count. Most notably was when venturing off the skin track at 10.7k on a sheltered but open NE slope. We experienced a medium sized collapse and watched cracks propagate in steeper adjacent terrain 100+ feet away. Cracks propagated ~150 feet across the steeper 33 degree slope but the slab did not run. We approached the most prominent crack (see photo, ski pole for reference) and dug down to find the failure point (second photo, crack left of probe). The denser snow from the last two storms has formed an approximately 30cm slab resting atop fragile surface hoar. I was able to pull several grains out (see photos). Overall depth in this area averaged ~100cm. The snowpack consisted of 40cm of fist hard facets near the ground from October, 27 cm of 4f slab from around thanksgiving, ~2cm of buried surface hoar and 30 cm of new snow from the last week.

We also saw multiple shooting cracks propagating shorter distances in BTL terrain from ski tips on slopes barely reaching 30 degrees. This sensitive weak layer, where it can be found is very reactive under minimal load.

Photos:

Location: Crested Butte Area
Date of Observation: 12/07/2019
Name: Ian Havlick

Subject: Coneys Pre-Storm Obs
Aspect: North, North East, East, South East
Elevation: 9,000-11,400

Avalanches:

no recent avalanches observed aside from a few small pockets mid-elevation across Slate River on Schuykill. Looked suspiciously like surface hoar but unverified. Old pockets that slid in late Novemeber have been skied over and blown in.

Weather: Mostly sunny transitioning to mostly cloudy by mid-afternoon. Some light NW winds at ridgetop, otherwise calm. Temperatures were rather mild in upper 20s, lower 30s.
Snowpack: Surprisingly supportable snowpack when breaking trail up far side Coneys. Ski pen ~20-30cm, Boot Pen easily to ground. Average height of snow (HS) 60-80cm. Deeper near ridgetop in wind drifted features. Several large collapses, a handful on the 3rd and 4th skiers in skin track. No significant cracking. Some minor wind transport on highest Baldy ridge line from NW winds, but nothing significant. Most notable was the widespread, large feather surface hoar all elevations. Will likely be preserved by Sundays snowfall and could be problematic in future.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/08/2019
Name:

Subject: Gothic 7 a.m
Aspect:
Elevation:

Weather: Some started around 3 a.m. and has been snowing moderately with heavily rimed crystals. Currently obscured with moderate snowfall and 2″ new with 0.29″ of water. Light SW wind but gusting at times. Snowpack at 17½”. billy

Location: Kebler Pass Area
Date of Observation: 12/07/2019
Name:

Subject: Snodgrass Obs
Aspect: North East
Elevation: 10,000

Avalanches:
Weather:
Snowpack: Surface hoar present everywhere we traveled. Large collapses in all open meadows we were in. ECTP2 & ECTP12. Failing 50cm down.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/07/2019
Name:

Subject:
Aspect: North, North East
Elevation: 11,000

Avalanches:

Large collapses, shooting cracks with wide propogation, small remote triggered avalanche

Weather:
Snowpack:

Photos:

Location: Paradise Divide Area
Date of Observation: 12/07/2019
Name: Eric Murrow

Subject: Slate River Look Around
Aspect: North, North East
Elevation: 9000′ to 10400′

Avalanches:

A handful of natural avalanches was observed along the Slate River Corridor.

Peeler Basin: 1xSS-R1-D2, NE, NTL
Schuylkill Ridge: 1xSS-R1-D1, NE, NTL
1xSS-R2-D2, NE, NTL
Cinnamon: 1xSS-D2ish, W, ATL
Schuylkill Peak: 1xSS-R2-D2, NE, NTL
Augusta: 1xSS-R1-D2, SE, ATL
Pittsburg “rollers area”: several D1’s on very small features facing N and E, BTL

Talking to other folks at the trailhead there are several more not included on this list in the Baxter Basin/Daisy Pass area.

Weather: Sunny day with moderate temperatures and light winds.

Snowpack: Traveled through terrain below treeline near Pittsburg in the same area as rider triggered slide from yesterday. Surface Hoar was present on the snow surface on aspects traveled (this will likely be buried on Sunday on northerly aspects below treeline (and maybe near treeline) and potentially be the 4th Surface Hoar layer buried in the snowpack this season). Multiple collapses were observed while traveling off of existing tracks and skinner. The snowpack remains talkative(collapsing) and showing signs of instability. The basal weak layers and multiple buried Surface Hoar layers are problematic and will be responsible for more avalanche activity during the next loading cycle later this weekend.

Stability tests performed adjacent to a recent triggered avalanche suggest that these weak layers are still capable of avalanches and will not require much of a new load before failure. Propagating ECT results and collapses encouraged conservative terrain choices.

The first photo below from Schuylkill Peak is a perfect example of the current multi-weak layered snowpack with three different failure planes visible in one avalanche.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/05/2019
Name: Evan Ross & Zach Kinler

Subject: Southerly Pow
Aspect: South, South West, West
Elevation: 9,700-11,800

Weather: Periods of heavy snowfall to no snow fall, all stacking up to about 9 to 12″ of new snow. Light wind, and mostly cloudy sky.
Snowpack: The new snow was nice and low density. We didn’t observe any significant issues on the old snow surface. At our upper elevation, the new snow had some slight drifting onto easterly facing terrain where it had some slight wind stiffening. A couple hand pits were able to pull very soft slabs on precipitation particles about 5-8cm’s above the old snow interface.

Southerly facing slopes had an HS varying 45-65cm’s. The crust on the ground made a great surface to ski on with new snow on top. The sun that made it through the clouds did start thickening up the new snow on some slopes.

Some lower angled slopes had a collapsible crust near the ground that produced a number of collapses. Also moving to westerly slopes and especially northwesterly slopes and the collapsible crust was more wide spread even on steeper terrain, or there was no crust and old weak snow near the ground. We skied some steep westerly slopes, but choose to route find around them on the way up. Shaded gullies and shaded portions of the slope behind tree fences were also avoided on steeper terrain.

Location: Paradise Divide Area
Date of Observation: 12/05/2019
Name: Evan Ross & Zach Kinler

Subject: Site Visit Of Human Triggered Avalanche Near Pittsburgh
Aspect: North East
Elevation: 10,200

Avalanches: Quick site visit of a recent snowboarder triggered avalanche.

This was a soft slab avalanche failing near the ground on a persistent weak layer of faceted grains. The avalanche size was large enough to bury a person. The avalanche ran for about 400ft of elevation loss and was about 100ft wide before gaining additional width as the avalanche moved down hill. The crown hight is estimated to be around 2.5ft, or 80cm. A snow profile at 9,800ft is in the picture below. In a brief summary there was 10 to 12″ of very soft new snow, over a 4F slab, sitting above the weak faceted grains below. Slope angles for this area are shown on CalTopo with slope shading in the 35-45 degree band, and further estimated to be at the lower half of that scale.